Explaining and testing radiation levels in groundwater has become a growing priority

Tokyo (CNN) -- Japan's health ministry announced Friday that there is no radioactive contamination of beef in the beleaguered country, saying an earlier report indicating there had been contamination was wrong.

A second examination of the same sample of beef confirmed the negative results to the health ministry.

The ministry said faulty testing may have led to the first result, which indicated levels of radiation slightly in excess of those allowed by Japanese law. In a second round of tests, lab workers were unable to find any trace of radioactive cesium in the same cattle, according to the reports.

Representatives from the town where the beef was from -- Tenei-mura, Fukushima -- have sent a written letter of protest to the governor, according to a report in the Asahi Shimbun newspaper.

"Was it necessary to release the first test result even though they knew they were conducting a second test?" questioned Tsukasa Kaneko, the chief of the village, according to the newspaper.

"To stop the release of early unconfirmed reports is the duty of the government, but now they have enflamed the situation and caused fear," the newspaper quoted him as saying.

Meanwhile Friday, tens of thousands of people who evacuated an area around the stricken Fukushima Daiichi power plant may not be allowed home for months, a Japanese minister said.

While he didn't set a firm timetable, Chief Cabinet Secretary Yukio Edano said people who had lived within 20 kilometers (12 miles) of the nuclear plant would not be returning home permanently in "a matter of days or weeks," as had been hoped.

"The evacuation period is going to be longer than we wanted it to be," Edano said. "We first need to regain control of the nuclear power plant."

About 78,000 people lived in the evacuation zone in northeast Japan. Another 62,000 lived within a 20- to 30-kilometer (12- to 19-mile) radius -- the so-called exclusion zone, where people have been told to stay indoors -- an official from Prime Minister Naoto Kan's office said.

The evacuees' plight is one of many storylines still playing out in relation to the crisis. At the embattled power plant, about 240 kilometers (150 miles) north of Tokyo, dozens of workers, soldiers and others are rushing to prevent the disaster from worsening.

Tokyo Electric Power Co. officials said they hope to place a camera in a maintenance tunnel to determine whether water is leaking from a joint of the trench, which could help to explain the troublesome spread of contaminated water around the plant.

Crews also sprayed 2,000 liters (more than 500 gallons) of synthetic resin meant to bind radioactive particles to the site and prevent them from spreading, according to Tokyo Electric. And huge concrete pumps described as the largest such machines in the world were being readied for delivery to the Fukushima plant as efforts continue to spray water onto the spent fuel pools and reactors at the plant to help keep the nuclear fuel cool.

Meanwhile, officials tried to sort out the impact of the crisis outside the plant's gates.

Authorities had previously banned the sale and transport of numerous vegetables grown in the area after tests detected radiation.

In the ocean offshore from the plant, the radioactive isotope cesium has been found in the sea at levels 527 times the regulatory limit. Questions remain about how it got there.

Radioactive iodine-131 also reached the ocean. Samples taken Wednesday 330 meters (360 yards) into the Pacific Ocean showed levels 4,385 times above the regulatory limit. This exceeded the previous day's reading of 3,355 times over the standard -- and was an exponential spike over the 104-times increase seen just last Friday.

Officials have downplayed the potential perils posed by the radioactive iodine, since it loses half of its radiation every eight days. All fishing is banned within 20 kilometers of the plant, and Hidehiko Nishiyama of Japan's nuclear safety agency adds that such waterborne radiation should dilute over time.

Concerns also remained about other water that has shown high levels of radiation.

This includes water in exposed maintenance tunnels leading into and out of the Nos. 1, 2, 3 and 4 reactor buildings, one of which earlier had radiation levels 100,000 above the norm.

Authorities have been working in recent days to drain these tunnels, to prevent them from spilling over and sending tainted water into the ground. By Friday, an official with TEPCO -- which operates the plant and heads the recovery effort -- said water levels had dropped one or more meters, and that the issue was no longer urgent.

Early Friday, a Tokyo Electric official said that iodine-131 levels in ground water from a pipe near the No. 1 reactor had 10,000 times the standard limit. But the utility later backtracked, promising to get more clarity later.

Edano addressed this confusion in a news conference later Friday, noting that a "constant amount of radiation" appeared to be getting into the groundwater while noting that further tests are forthcoming.

"The numbers released ... looked strange, and that led to the recalculation," he said. "In either case, underground water seems to contain some level of radioactive substances, and this leads to an understanding that the ... soil in the vicinity needs to be monitored closely."

All this contamination -- both into the ground and, eventually, the sea -- is the result of a leak or some other sort of ground seepage from one of the nuclear plant's four most embattled reactors, a Tokyo Electric official said Thursday. The official noted that the high levels suggest the release of radiation into the atmosphere alone couldn't be the lone source.

While conditions at the plant continued to be dire, conditions for workers struggling to get the facility under control appeared to be improving somewhat.

Workers now have access to a greater variety of foods and drinks, including vegetable juice, soup, bread and military-style food rations, a Tokyo Electric representative said. Officials have also converted a gym at the plant into a dormitory for workers, with tatami mats on the floor to accommodate 500 people, according to the utility.

Kan said Friday that Tokyo Electric will pay a steep price for the nuclear crisis -- and that the government could end up footing some of that expense.

A report released this week by the Bank of America Merrill Lynch estimated that compensation claims alone, with payouts going to those most adversely affected by the nuclear crisis, could rise to between 1 trillion Japanese yen (about $12 billion) in compensation claims if the recovery effort lasts two months, or up to 10 trillion yen if it goes on for two years.

"If the costs are beyond the means of Tokyo Electric, the government should take part," Kan said, before adding that as a "private institution, (the utility company) has to do their best."

Beyond dealing with the financial ramifications, Kan also promised to address long-term safety concerns as well. He said that, while Japan wouldn't necessarily abandon nuclear power, it will re-evaluate its power plan once the situation stabilizes at the Fukushima Daiichi plant.

"We will have strong risk-management measures in place, in some cases even if they're considered too extreme," he told reporters. "We will (guard against) every possible scenario."